


Regeneration

by heghlumeH



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/F, F/M
Language: English
Status: Completed
Published: 2020-10-24
Updated: 2020-10-24
Packaged: 2021-03-08 22:41:33
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,812
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27173989
Author URL: https://archiveofourown.org/users/heghlumeH/pseuds/heghlumeH
Summary: A crest stone's like a second heart. Byleth gets to cheat death and put on a new face, and Edelgard gets to worry.
Relationships: Edelgard von Hresvelg/My Unit | Byleth
Comments: 1
Kudos: 22





	Regeneration

**Author's Note:**

> I had a very stupid passing thought. Ostensibly a Doctor Who crossover, but not tagged as such since it doesn't actually "cross over." I've just er, borrowed a concept for the sake of a gag, more or less.

The Professor had said he would be "right back." Edelgard had not known the Professor to break his promises. Although it was seldom said explicity, she had also known that his strange and enthusiastic sincerity to which he took to everything meant that very nearly everything he said he would do was something he would make good on. So, wistfully, and feeling like a hopelessly naive little girl all the while, Edelgard had taken to periodic checks on the Garreg Mach Monastery. Once a month, every month, for five years. No, she wasn't obsessed, and no, she wasn't "in love" with the Professor, and no, she most certainly did not sit in windowsills and stare longingly into the distance for him. 

This would be the fifty-eighth time she had checked in on the old academy. She kept track of which check she was on, because it was very important to all was keep good record of these things, and since it was so obvious that this was the case, it bore repeating. Again, not obsessed. As her fifty-eighth session fruitless monastery scouring came to a close, Edelgard's purely platonic thoughts of regretful longing were interrupted by a crash that caused the ground to quake and the ancient seismically-unprepared stone structure to fracture in places. Before she could muse on how this blatant disregard for safety protocols were yet another in a long list of church injustices, Edelgard's thoughts were once again interrupted, this time by a flash of golden light. 

With not one, but two highly unusual omens in one night, Edelgard gleefully abandoned her usual pessimism in favour for barely disguised anticipation. Barely disguised, of course, because there was nothing to disguise. Edelgard was merely glad to entertain the possibility that the teacher of the Black Eagles was returning, and after all, everyone knew that the Professor was an adept instructor in all things martial, and that his lessons to the class were invaluable towards the...

Distantly, a certain songstress felt a strange sense of mild regret wash over her, as though a close friend were gushing about a certain someone and she wasn't there to needle her about it.

Deciding that there would be more time later to properly list out all of her Professor's valued contributions, which she knew to be extensive, Edelgard cut herself off short in order to run towards the source of the light. Frantically running towards a tiniest sliver of hope that her Professor may have returned (unsubstantiated by any real evidence) obviously required all of her attention. Once again, purely platonic, no pining whatsoever. Rounding the corner, she was met with a sight she had long dreamt of. 

Bracing himself against the wall so that only his back was visible, Edelgard saw that characteristically bizarre yet endearing choice of attire that only the Professor would dare to wear. For only Professor Byleth, the Ashen Demon, Son of the Blade Breaker, Wielder of the Sword of the Creator, would cut additional holes into his clothing so that he may slide his arms through in a bizarre, houppelande-imitating hybrid of cape and coat. Yes, she had dreamt of seeing the houppelande-cape-coat again someday, but only in a figurative sense and definitely not literally. 

There were a few... discrepancies... between her memory of the Professor and the Professor that stood before her now. For one, he seemed shorter. Or perhaps Edelgard had grown taller without her realizing? A petty thing for sure, but in the fifty-eight months of war, the Emperor had been left behind as the smallest of her inner circle. Even Lysithea now stood taller, and Ferdinand had the absolute gall to grow another 5 centimetres, as if his sole (and literal) victory over her needed reinforcing. Perhaps recruiting the still-tiny Dominic girl was in order. Pushing that particular flight of fancy aside, the Professor was definitely shorter. Shorter, and while the houppelande-cape-coat did much to conceal his figure, he seemed... somehow less bulky.

His hair, as well, seemed different. Well, more different. The Minty Green colour remained, but it had grown out considerably. This change could easily be attributed to the long gulf of time he had been missing, but for his hair to shine the way it did... It would have had to have been a remarkably relaxing 5 years if he was finding the time to style it.

Still, the all signs pointed to her dear Professor. Her belov- Her very much appreciated and valued Professor. The Black Eagle Strike Force would say he had returned from the dead, but Edelgard never stopped believe. He had returned to her. Her patience had been rewarded. Were she still capable of tears she would weep. 

"Professor?" Edelgard asked, probingly, still harbouring just the smallest amount of doubt, a bit of emotional insurance to spare herself the heartbr- immense disappointment, should what ought to be Byleth not be Byleth.

"Edelgard!" came the reply, in a stranger woman's voice, spinning around, with the edges of her lips curved into the smallest of smiles.

Oh no. Oh no no no no. Edelgard knew she shouldn't have gotten her hopes up. She knew that she shouldn't have projected the Professor's image onto such passing superficial similarities. She was a fool for thinking only the Professor's taste in clothing could be so strange. She was a fool for assuming that Rhea and her ilk were the only ones apart from the Professor who could have that colour of hair. She was a fool for looking into the stranger woman's eyes and seeing those same, piercing blue eyes, and noticing how her little hint of a smile was the same as the Professor's. She was a fool for... for... for noticing that the stranger woman wore literally the exact same clothing as her Professor did, that seemed to hang off her shoulders loosely and sag, save for the chest, where Edelgard would now proceed to not focus too hard on in the interest of politeness. 

"M-my apologies," came Edelgard's halting reply "I thought you were my Professor, are you perhaps his sister?"

The stranger woman's tiny smile inverted itself into a tiny frown. _cute_ , Edelgard found herself thinking, in spite of herself. 

"Are you all right, Edelgard? I said I would be just a minute. Had to go find a safe place to die, but now that that's over with, I'm here! Right back, just like I said! Might've taken a bit longer than I intended though, you've had time to change and it sounds like the battle is over. You look good, by the way."

Edelgard gaped at her for a moment before re-collecting herself, and continued to press the woman, adopting a much more sterner, authoritative tone. In part in the hopes that she might glean something new, and in part as a way to simply soothe her own nerves.

"Who are you, what are you doing here, and what do you hope to achieve?"

The stranger woman's brow furrowed, ever so slightly. _Just like the Professor's_ would.

"It's... me, Edelgard. Professor Byleth."

"You are not the Professor. The Professor is a man."

"I _am_ a- oh, huh." The stranger woman took a moment to, for a lack of a better term, _admire_ herself, twisting and turning herself around all to get a better look at herself. "That would account for the weight I feel on my chest."

Once more, Edelgard looked only to confirm this fact. Nothing more. 

"I guess I'm also a bit shorter. I thought you'd gotten taller!"

Edelgard's face warms a little at that. "Please do not mock me."

"I wouldn't dream of it!" the woman quickly replied, her faint look of indignation slowly morphing into one of faint mirth, "but I would tease you about it."

Edelgard says nothing, but continues to glare at the woman with suspicion. After a moment, a look of understanding comes over the stranger woman's face.

"Ah, I see. Edelgard von Hresvelg, my name is Byleth Eisner. I am the son, er, daughter, of Jeralt the Blade Breaker, and the Professor of the Black Eagles at the Garreg Mach Monastery's Officer Academy. I possess the Major Crest of Flames and wield the Sword of the Creator..." she fumbled at the empty scabbard at her hip "...which I seem to have misplaced. I watched you be crowned Emperor of Adrestria. I know you suffer from night terrors, and I know that you love Bergamot beyond all others."

"Your initial claim is outlandish, and the details you cite as proof are those that could easily be uncovered with little effort. I have no reason to believe that you are who you claim to be, or are not in fact another one of my _dear Uncle's_ agent's."

"I know that you value your friendship with Petra, for you could have easily been bitter rivals. I know you dote on Lysithea like a little sister because she's the closest thing you have left to a family. I know you like to sneak in some extra desert when you think no-one is looking. I know how much you love that stuffed bear dressed in armour I got you, and how quickly you hid him away when I came knocking on your door that one time, and how relieved you were when I said I didn't hear anything but in actuality, I overheard that you had named him-"

Seeing Edelgard's face turn as red as her armour was Byleth's cue to stop. A small part of him- er, her, was just a little bit disappointed. He had more stories he knew she would be mortified to learn that he remembered, and she was fun to tease. 

The girl who no longer wept looked dangerously close to doing so. 

"It really is you, Professor." 

"I always will be." 

* * *

"Where have you been all this time?"

"Don't tell me I overshot by all that much. How long has it been. A day? A week? A month? No... a year? If I've gotten shorter, then that means you can't have grown much taller at all, and if that's the case, then it couldn't have been very long."

"It's been 5 years, Professor. Please stop bringing up my height, and please answer my question."

"5 whole years? Wow. Five years. Half a decade. I've missed a lot, haven't I?"

"Yes, you have. Professor, please, I must know where you have been."

"Well, I was aiming for a few hours. Hopped into my SOTHIS for safety and tried to be back the same night. Guess I must've accidentally pushed a button or something and then poof, 5 years gone."

"Your what?"

"Saintly Ordained Temporal Hopper In Space."

"That rather sounds like you torturously worked backwards from the name Sothis to get the acronym."

"I might have." 

* * *

"Edelgard?"

"Yes, Professor?"

"I think I will need new underwear."

Edelgard's face burned. 

**Author's Note:**

> Ideas for the swap in the other direction, consisting entirely of costume-related comments.  
> "I don't fill out the chest area as well as I used to."  
> "These leggings continue to show off my legs quite well."  
> "I was skeptical about keeping the abdominal window, but I think it flatters me."


End file.
